Decorative article having inorganic coating film having rugged pattern including cracks and process for production thereof

ABSTRACT

A decorative article having a patterned coating film, which is obtained by coating a substrate with a coat of silicate type inorganic paint, applying thereon a coat of a solution of an acid or acidic salt in water and/or an alcohol while the applied coat of paint is in the semi-hardened state, allowing the coated substrate to stand, removing the excess solution by waterwashing, and drying the thus treated substrate to harden the coating.

United States Patent Makishima et al.

1 1 Aug. 19, 1975 DECORATIVE ARTICLE HAVING INORGANIC COATING FILM HAVING RUGGED PATTERN INCLUDING CRACKS AND PROCESS FOR PRODUCTION THEREOF Inventors: Hiroshi Makishima. Yokohama;

Toshio Shinohara, Fujisawa; Yukio Kawahara, Yokohama; Hiroshi Nii. Kamakura, Setsuo Ebine. Yokohama. all ofJapan Assignee: Dai Nippon Toryo Co., Ltd.,

Osaka. Japan Filed: Dec. 28, 1973 Appl. No.: 429,175

Foreign Application Priority Data Dec. 29, 1972 Japan 47-3719 US. Cl. 428/155; 427/257; 427/333;

428/446; 428/454 Int. Cl 344d 5/00 Field of Search 117/41, 45, 62, 62.1, 62.2,

[56] References Cited UNITED STATES PATENTS 1,818,729 8/1931 Marmorstein 117/41 3.560141) 2/1971 Simmons v 117/41 3,635,858 l/l972 Shiratori 260/22 R OTHER PUBLICATIONS Hess, Paint Film Defects, Chapman and Hall, Ltd., London, 1965, Figs. 5, 61 and 62.

Primary E.\'aminerTh0mas J. Herbert, .lr. Assistant ExaminerBruce I-I. Hess Attorney, Agent, or Firm-Waters, Schwartz & Nissen 5 7 1 ABSTRACT 11 Claims, 6 Drawing Figures PATENTEUAUGIQIQYS 3,900,630

sum 2 o 2 U FC i f I" I \AM -c DECORATIVE ARTICLE HAVING INORGANIC COATING FILM HAVING RUGGED PATTERN INCLUDING CRACKS AND PROCESS FOR PRODUCTION THEREOF BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a decorative article having an inorganic coating film having a rugged pattern including cracks, and to a process for the production thereof.

More particularly, the invention relates to a decora tive article comprising a substrate such as a metal, wood or ceramic product and an incombustible film coating of the silicate type inorganic paint having a beautiful pattern, which is formed on said substrate, and to a process for preparing such decorative articles very simply and conveniently.

2. Description of the Prior Art Paints comprising as a vehicle an organic material such as a synthetic resin have heretofore been applied on construction materials and the like broadly in various fields. In a fire, however, poisonous gases such as carbon monoxide, chlorine and hydrogen cyanide are generated by these paints and poisonous smoke is generated by the organic materials contained in the paints, causing many casualities. Accordingly, incombustibility is now required not only of construction materials and interior decoration materials but also paints.

Paints of water glass type, i.e., the alkali metal silicate series, have long been known as incombustible paints. For example, there are known paints including as a vehicle potassium silicate (U.S. Pat. Nos. 3,077,389 3,389,002 3,493,401 and 3,522,133), sodium silicate (U.S. Pat. No. 3,492,137) or lithium silicate (U.S. Pat. Nos. 3,356,515 and 3,392,039). As a silicate type composition free from an alkali metal silicate, there is known a composition comprising an organic ammonium silicate and incorporated therein, a binder such as boric acid and phosphoric acid (U.S. Pat. Nos. 3,248,237 and 3,345,194). As a paint composition having especially good fire-proofing or fire-preventing property, there has been proposed a composition comprising as a binder sodium silicate (U.S. Pat. No. 2,991,200), a composition comprising sodium hexametaphosphate incorporated in said binder (U.S. Pat. No. 3,639,276), and a composition including a combination of an alkali metal silicate and an organic silicone (U.S. Pat. No. 3,493,401).

Further, as a special coating composition, there is known a composition comprising an alkali metal silicate and a curing agent composed of a water-alcohol solution of a chloride or sulfate of calcium, cobalt, magnesium or the like and nitric acid, sulfuric acid, fumaric acid or acetic acid (U.S. Pat. No. 3,258,346).

Still further, as a special coating process, there is known a process comprising coating an aluminum oxide film with an alkali metal silicate, and immersing the applied coat into a solution containing a fluoride after complete hardening of the coating, thereby removing alkali metal ions (U.S. Pat. No. 3,625,737).

In each of the foregoing known conventional techniques, only a smooth finished surface is obtained by coating a substrate with an inorganic paint. Currently, however, in addition to smooth finished coatings, there is a demand for decorative coatings having a variety of rugged patterns.

As is seen from the foregoing explanation of the prior techniques, neither an inorganic paint coating having a patterned surface nor a process for the production of such coating has been known in the art, and hardly any research has been made in this field.

SUMMARY OF THE INVENTION This invention is directed to an inorganic paint coating having a patterned surface which, as pointed out above, has not been known in the art, and to a process for the preparation thereof.

The objects of this invention are as follows:

1. To obtain a decorative article having an inorganic paint coating having a rugged pattern or a pattern of cracks or chaps.

2. To obtain a decorative article having a patterned inorganic paint coating which has a multi-colored finish in which the color of the pattern portion is different from the color of the smooth portion.

3. To obtain a decorative article having a patterned coating which exhibits good adhesion to a substrate.

4. To obtain an incombustible coating film.

In accordance with this invention, the foregoing objects can be attained by a process comprising the steps of coating a substrate with a coat of an inorganic paint of the silicate type, applying thereon a solution of an acid or acidic salt in water and/or an alcohol while the applied coat of paint is in the semi-hardened state, allowing the coated substrate to stand, removing the excess solution by water-washing, and drying the thus treated substrate to harden the coating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a decorative plate having on the entire surface thereof a coating having a rugged pattern including cracks, which is obtained by practicing the process of this invention;

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a front view illustrating a decorative plate comprising an inorganic coating having a rugged pattern including cracks and a smooth primer layer;

FIG. 4 is a sectional view taken along line 8-8 in FIG. 3;

FIG. 5 is a front view of a decorative plate having a partially patterned coating, which is obtained by practicing the process of this invention; and

FIG. 6 is a sectional view taken along line C--C in FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION Inorganic paints of the silicate type to be used in this invention include as a vehicle a silicate represented by the following general formula 65 by the formula N=C(NH or CH CH Specific examples of the silicate to be used in this invention are sodium silicate, potassium silicate, lithium silicate, ammonium silicate, morpholine silicate, guanidine silicate, and silicates of amines such as monomethanol amine, monoethanol amine, dimethanol amine, diethanol amine, trimethanol amine, triethanol amine, tetramethanol amine, tetraethanol amine, monomethyl amine, monoethyl amine, dimethyl amine, diethyl amine, trimethyl amine, triethyl amine, tetramethyl amine and tetraethyl amine. These silicates can be used singly, or mixtures of two or more of them can also be employed.

Inorganic paints to be used in this invention are formed by adding suitable amounts of water and a hardening agent to a vehicle such as mentioned above and if necessary, further adding an organic or inorganic pigment, a dispersing agent or other additive.

Any of the hardening agents customarily used for silicate paints can be used in this invention. Examples of such hardening agents are powders of metals such as zinc, lead and aluminum, metal oxides such as magnesium oxide, zinc oxide, aluminum oxide, lead oxide, calcium oxide and chromium oxide, metal hydroxides such as magnesium hydroxide, zinc hydroxide, aluminum hydroxide and lead hydroxide, fluorides such as sodium fluoride and sodium silicofluoride, phosphates such as aluminum pyrophosphate and magnesium pyrophosphate, carbonates such as magnesium carbonate, sulfates such as magnesium sulfate, and carbon dioxide gas and the like.

These hardening agents can be used as they are or in the form of an aqueous solution or dispersion. These hardening agents can be used singly or in the form of mixtures of two or more of them. They are applied in the form of a so-called one-liquid type paint composed of such hardening agent and a silicate such as mentioned above. It also is possible to use a so-called twoliquid type paint, namely by mixing the hardening agent with the above-mentioned silicate in situ at the time of application. It is preferred that the hardening agent'be used in an amount of 4 to 30% by weight based on the silicate. In a special embodiment of this invention, the above-mentioned silicate vehicle is applied on a substrate and then the vehicle is hardened in an atmosphere of carbon dioxide gas as the hardening agent.

Any organic and inorganic pigments that are used for ordinary coating compositions can be used in this invention, and in some cases, dyes can be used as colorants.

In this invention the acid or acidic salt is used in the form of a solution in water and/or an alcohol.

Alcohols having a solubility in water at C exceeding 20% are used for formation of solutions of acids or acidic salts. For example, there can be mentioned methyl alcohol, ethyl alcohol, isoppropyl alcohol, npropy] alcohol, sec-butyl alcohol and tert-butyl alcohol. These alcohols can be used singly or mixtures of two or more of them can be employed.

As the acid to be used in the form of an aqueous solution, there can be mentioned, for example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, nitric acid and carbonic acid, and organic acids such as formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid and glutaric acid. It is preferred that the acid be used in the form of an aqueous solution having a concentration of 5 to 40% by weight. It also is preferred that the solubility of the acid in water at 20C exceed 5% and its aqueous solution be acidic.

As the acid to be used in the form of an alcohol solution or a solution in a mixture of water and an alcohol, there can be mentioned, for example, inorganic acids such as phosphoric acid and boric acid and organic acids such as formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid and glutaric acid. The acid is preferably used in the form of a solution having a concentration of 5 to 40% by weight. It is desired that the solubility of the acid in the alcohol at 20C be higher than 5%.

Salts, aqueous solutions of which are acidic, are employed as the acidic salt in the form of an aqueous solution in this invention. As such acidic salt, there can be mentioned, for example, chlorides such as aluminum chloride, zinc chloride, barium chloride and magnesium chloride, sulfates such as aluminum sulfate, zinc sulfate and magnesium sulfate, nitrates such as aluminum nitrate, zinc nitrate and calcium nitrate, and phosphates such as aluminum primary phosphate, zinc primary phosphate and sodium primary phosphate. These salts are used in the form of an aqueous solution having a concentration of 10 to 40% by weight. It is desired that the solubility of the acidic salt in water at 20C be higher than 5%.

As the acidic salt to be used in the form of an alcohol solution or a solution in a mixture of water and an alcohol, there can be mentioned, for example, chlorides such as aluminum chloride, zinc chloride and magnesium chloride, sulfates such as aluminum sulfate, zinc sulfate and magnesium sulfate, and nitrates such as aluminum nitrate, zinc nitrate and calcium nitrate. These acidic salts can be used singly, or mixtures of two or more of them can also be employed. It is preferred that they be used in the form of a solution having a concentration of 10 to 40% by weight. It also is preferred that the solubility of such acidic salt in the alcohol at 20C be higher than 5%.

In the process of this invention, the substrate is coated with the silicate type inorganic paint preferably in an amount of 50 to 500 g/m according to customary procedures.

As the substrate to be used in this invention, there can be mentioned, slate plates, glass plates, metal plates (aluminum plate, iron plate, steel plate, etc.), wood, mortar, plywood, plastics and the like. A variety of decorative plates formed by applying in advance an appropriate sealer or primer, a silicate type inorganic paint such as mentioned above or a phosphate type in organic paint can also be employed as the substrate in this invention.

After application of the silicate type inorganic paint. the coated substrate is dried at room temperature, or it is positively dried at 30 to 150C, preferably 50 tc C, for a short time, whereby a semi-hardened coating film is obtained.

In this invention it is important that the drying be conducted so that the coated paint is in the semihardened state. In other words, when the applied inorganic paint is completely hardened (generally by heating it at to 250C for 10 to 60 minutes), it does not at all react with the solution of the acid or acidic salt in water and/or an alcohol, which is applied in the next step, and hence, it is impossible to obtain the intended patterned coating. The semi-hardened state referred to in the instant specification and claims ranges from the tack free state to the dry hard state just prior to complete hardening.

A solution of the acid or acidic salt in water and/or an alcohol is applied on the semi-hardened coating film by means of a sprayer, a flow coater, a roll coater, a brush or the like. The solution can be applied on the entire surface of the inorganic paint coating film or a part of the surface thereof.

When the solution of the acid or acidic salt in water and/or an alcohol is applied on the semi-hardened paint coating film, hardening of the coating film is abruptly accelerated and in some cases water absorption by the alcohol is caused, whereby non-uniform shrinkage is brought about on the coating film to form cracks and chaps at random on the surface of the coating.

In the process of this invention, after application of the solution of the acid or acidic salt in water and/or the alcohol, the coated substrate is allowed to stand for from 0.5 to 30 minutes, preferably about minutes, to form a pattern on the surface thereof, and it is then water-washed to remove the excess solution of the acid or acidic salt in water and/or the alcohol. If this water washing step is omitted, the coating film obtained after the final hardening and drying step undergoes blushing or the like, and it is impossible to obtain a decorative article having a beautiful coating.

The coating film is then naturally dried or baked under heating (usually at 150 to 250C for 10 to 60 minutes) until even the interior of the coating of the inorganic paint is completely hardened, whereby the intended patterned article is obtained.

In this invention, in order to improve the surface appearance of the resulting article or other physical properties, it is possible to coat the patterned article with an inorganic or organic clear paint.

The decorative article having an inorganic coating having a rugged pattern including cracks, which is obtained by practising the process of this invention, for example, a decorative plate, has a surface appearance such as shown in FIGS. 1 or 3. Thus, the pattern referred to in the instant specification and claims includes patterns ranging from a pattern of fine chaps such as represented by l in FIG. 1 to a pattern of branched cracks such as represented by 5 in FIG. 3.

In this invention, it is possible to form a patterned coating according to the above process on a preformed coating obtained by applying an inorganic paint on the substrate and completely hardening it by heating or the like (see FIG. 3). In this case, if the color of the pre-formed primer coating 8 is made different from the color of the coating 6 of the silicate type paint, there can be obtained a decorative article having a multicolored pattern of at least two colors in which the color of the primer coating, visible at areas 5 of the crack pattern, is different from the color of smooth surface areas 6. Further, in this case cracks 7 which do not reach the primer layer are formed, which are effective for giving a soft appearance to the surface of the resulting article.

Moreover, the patterned decorative article of this invention is advantageous in that the inorganic paint coating layer cannot be simply peeled by abrasion or impact.

This invention will now be illustrated in more detail by reference to the following Examples, in which part and are on a weight basis unless otherwise indicated.

EXAMPLE I An inorganic paint having the following formulation 1 was mixed and kneaded, spray-coated on a slate plate and positively dried at 60C for 10 minutes.

Inorganic Paint Formulation 1 aqueous solution of potassium silicate (non-volatile content 25.3%) 50 parts aqueous solution of sodium silicate (non-volatile content 37.6%) 17 parts diatomaceous earth 5 parts kaolin clay 8 parts titanium white 15 parts magnesium carbonate 5 parts total parts A 5% aqueous solution of I-ICl was applied to the resulting semi-hardened coating film by means of a brush, and the coated'substrate was allowed to stand for 10 minutes, following which water washing was conducted. Then, the thus treated substrate was dried to obtain a product having an inorganic paint coating having a beautifulpattern of cracks. This patterned inorganic paint coating has very excellent adhesion to the slate plate substrate.

The thus obtained patterned article is shown in FIGS. 1 and 2, in which reference numerals 1, 2, 3 and 4 indicate a crack portion, a smooth portion, an inorganic paint coating and a slate plate substrate, respectively.

EXAMPLE 2 A paint of the formulation 1 shown in Example 1 was spray-coated on a glass sheet and positively dried at 80C for 5 minutes to obtain a semi-hardened coating. Then, a 30% aqueous solution of MgCl was spraycoated on the thus obtained semi-hardened coating, and the coating was allowed to stand for about 10 minutes, following which water washing was conducted and the coating was baked at C for 30 minutes to harden the coating completely. There was obtained a product having a coating of a beautiful pattern.

EXAMPLE 3 A paint of the formulation 1 shown in Example 1 was spray-coated on a steel plate and positively dried at 60C for 10 minutes to obtain a semi-hardened coating film. Then, a 25% aqueous solution of phosphoric acid was flow-coated on the thus obtained semi hardened coating film, and it was allowed to stand for about 10 minutes. Then, the thus treated coating film was waterwashed and baked at 180C for 30 minutes to attain complete hardening. There was obtained a product having a coating of a beautiful pattern.

EXAMPLE 4 A paint of the formulation 1 shown in Example 1 was spray-coated on a slate plate and positively dried at 60C for 5 minutes to obtain a semi-hardened coating film. Then, a 20% aqueous solution of ZnCl was applied on the thus obtained semi-hardened coating by means of a brush, and the coating was allowed to stand for about 15 minutes, was washed with water and baked at 180C for 30 minutes to complete hardening of the coating. There was obtained a product having a coating of a beautiful pattern.

EXAMPLE EXAMPLE 6 An inorganic paint of the following formulation 2 was mixed and kneaded, spray-coated on a slate plate and baked at 180C for 30 minutes to obtain a completely hardened coating film.

Inorganic Paint Formulation 2 aqueous solution of potassium silicate 50 parts (non-volatile content 27.3%)

aqueous solution of sodium silicate 17 parts (non-volatile content 37.6%)

diatomaceous earth 5 parts kaolin clay 8 parts red iron oxide 15 parts magnesium carbonate 5 parts Then, an inorganic paint of the formulation 1 shown in Example 1 was spray-coated on the thus obtained, completely hardened coating film, and the coating was positively dried at 60C for minutes to obtain a semihardened coating film. Then, a 5% aqueous soluion of HCl was applied on the thus obtained semi-hardened coating by means of a brush, and it was allowed to stand for about 10 minutes, was washed with water and dried at room temperature to obtain a completely hardened coating as shown in FIGS. 3 and 4. There was obtained a product having a coating of a beautiful pattern in which a crack portion 5 was colored red and the remaining portion 6 was white.

EXAMPLE 7 An inorganic paint of the formulation 2 shown in Example 6 was spray-coated on a glass sheet and baked at 180C for 30 minutes to obtain a completely hardened coating. Then, an inorganic paint of the formulation 1 shown in Example 1 was spray-coated on the thus obtained, completely hardened coating, and it was positively dried at 80C for 5 minutes to obtain a semihardened coating film. Then, a 30% aqueous solution of MgCl was applied on the thus obtained semihardened coating, and the coating was allowed to stand for about 10 minutes, was washed with water and baked at 180C for 30 minutes to harden the coating completely. There was obtained a patterned product having a beautiful surface resembling that of the product obtained in Example 6.

EXAMPLE 8 An inorganic paint of the formulation 1 shown in Example l was spray-coated on a steel plate and baked at 180C for 30 minutes to obtain a completely hardened coating film. An inorganic paint of the formulation 2 shown in Example 6 was spray-coated on the thus obtained, completely hardened coating, and the resulting coating was positively dried at 60C for 10 minutes to obtain a semi-hardened coating. Then, a 25% aqueous soluion of phosphoric acid was flow-coated on the thus obtained semi-hardened coating, and it was allowed to stand for about 10 minutes, was washed with water and dried at 180C for 30 minutes to obtain a product having a coating of a beautiful pattern.

EXAMPLE 9 An inorganic paint of the formulation 1 shown in Example 1 was spray-coated on a slate plate and baked at 180C for 30 minutes to harden completely the coated paint. Then, an inorganic paint of the formulation 2 shown in Example 6 was spray-coated on the thus obtained, completely hardened inorganic paint coating,

and then positively dried at 60C for 5 minutes to obtain a semi-hardened coating film. Then, a 20% aqueous solution of ZnCl was spray-coated on the thus obtained semi-hardened coating, and the coating was allowed to stand for about 15 minutes, was washed with water and baked at 180C for 30 minutes to obtain a product having a coating of a colored pattern, the color arrangement of which was quite contrary to that of the product obtained in Example 6.

EXAMPLE 10 An inorganic paint of the formulation 2 shown in Example 6 was spray-coated on a slate plate and baked at 180C for 30 minutes to obtain a completely hardened coating. Then, an inorganic paint of the formulation 1 shown in Example 1 was spray-coated on the thus obtained coating, and the paint was positively dried at C for 10 minutes to obtain a semi-hardened coating.

Then, a 30% aqueous solution of acetic acid was ap- I plied on the thus obtained semi-hardened coating by EXAMPLE 1 1 An inorganic paint of the following formulation 3 was spray-coated on an aluminum plate and was positively dried at 60C for 10 minutes to obtain a semi-hardened coating film.

Inorganic Paint Formulation 3 aqueous solution of potassium silicate 20 parts (non-volatile content 25%) aqueous solution of sodium silicate 30 parts (non-volatile content 40%) aqueous solution of lithium silicate 28 parts (non-volatile content 25%) diatomaceous earth 3 parts talc 4 parts titanium yellow 10 parts calcium fluoride 5 parts total parts Then, a 20% solution of aluminum chloride in ethanol was spray-coated on the semi-hardened coating, and the coating was allowed to stand for about 10 minutes, was washed with water and dried at room temperature to effect complete hardening of the coating. There was obtained a product having a coating of a beautiful pattern of cracks.

EXAMPLE 12 An inorganic paint of the formulation 1 shown in Ex ample l was spray-coated on a glass plate and positively dried at 60C for 5 minutes to obtain a semihardened coating film. Then, a 25% solution of magnesium chloride in ethanol was applied on the semihardened coating by means of a roll coater, and the coating was allowed to stand for minutes, was washed with water and baked at 180C for 30 minutes to harden the coating completely. There was obtained a product having a coating of a beautiful pattern.

EXAMPLE 13 An organic paint of the formulation 2 shown in Example 6 was spray-coated on a glass plate and positively dried at 80C for minutes to obtain a semihardened coating film. Then, a 30% solution of zinc nitrate in ethanol was spray-coated on the semi-hardened coating, and the coating was allowed to stand for 10 minutes, was washed with water and baked at 180C for 30 minutes to harden the coating completely. Thus was obtained a product having a coating of a beautiful pattern.

EXAMPLE 14 EXAMPLE 15 An inorganic paint of the following formulation 4 was spray-coated on a wood board and baked at 180C for 30 minutes to obtain a completely hardened coating film.

Inorganic Paint Formulation 4 aqueous solution of potassium silicate 33 parts (non-volatile content aqueous solution of sodium silicate parts non-volatile content 40%) aqueous solution of ammonium silicate 10 parts (non-volatile content 40%) kaolin 6 parts tale 5 parts iron oxide l0 parts zinc flower 5 parts total 100 parts Then, an inorganic paint of the formulation 1 shown in Example 1 was spray-coated on the thus obtained primer coating film, and was positively dried at 60C for 10 minutes to obtain a semi-hardened coating. Then, a mixed solution composed of 20% of zinc chloride, 70% of water and 10% of ethanol was applied on the thus obtained, semLhardened coating by means of a brush, and the semi-hardened coating was allowed to stand for about 10 minutes, was washed with water and baked at 180C for 30 minutes to obtain a product having a coating of a beautiful pattern.

EXAMPLE 16 An inorganic paint of the formulation 2 shown in Example 6 was spray-coated on a glass sheet and baked at 180C for 20 minutes to obtain a completely hardened coating film. Then, an inorganic paint of the formulation 3 shown in Example 11 was spray-coated on the thus obtained primer coating and positively dried at 60C for 10 minutes to obtain a semi-hardened coating film. Then, a mixed solution composed of 20% of magnesium sulfate, 20% of methanol, 40% of ethanol and 20% of water was applied on the semi-hardened coating by means of a flow coater, and the semi-hardened coating was allowed to stand for about 10 minutes, was washed with water and baked at 180C for 30 minutes to obtain a product having a coating of a beautiful pattern.

EXAMPLE 1 7 An inorganic paint of the formulation 3 shown in Example l was spray-coated on a slate plate and baked at lC for 30 minutes to obtain a completely hardened coating film. Then, an inorganic paint of the formulation 4 shown in Example 15 was spray-coated on the thus obtained, completely hardened coating, and the coated paint was positively dried at 80C for 5 minutes to obtain a semi-hardened coating film. Then, a solution composed of 15% of formic acid, 50% of ethanol and 35% of water was applied on the semi-hardened coating by means of a brush, and the coating was allowed to stand for about 10 minutes, was washed with water and baked at l80C for 30 minutes to obtain a product having a patterned coating.

EXAMPLE 1 8 An inorganic paint of the formulation 2 shown in Example 6 was spray-coated on a steel plate and baked at C for 30 minutes to obtain a completely hardened coating film. Then, an inorganic paint of the formulation 4 shown in Example 15 was spray-coated on the thus obtained primer coating and positively dried at 60C for 5 minutes to obtain a semi-hardened coating. Then, a solution composed of 5% of boric acid, 15% of water and 80% of ethanol was spray-coated on the thus obtained semi-hardened coating, and the coating was allowed to stand for about 10 minutes, was washed with water and baked at 180C for 30 minutes to obtain a product having a patterned coating.

EXAMPLE 19 An inorganic paint of the formulation 1 shown in Example l was spray-coated on a glass sheet and positively dried at 80C for 1 minute to obtain a semihardened coating film. Then, a 5% aqueous solution of hydrochloric acid was applied on a part of the thus obtained semi-hardened coating by means of a brush. Post treatments were conducted in the same manner as described in Example 18 to obtain a product having a patterned coating.

The thus obtained patterned product is shown in FIGS. 5 and 6, in which reference numerals l0, ll, 12 and 13 indicate a cracked portion, a smooth portion, an

inorganic paint coating film and a glass sheet substrate, respectively.

EXAMPLE 20 An inorganic paint of the formulation 1 shown in Example 1 was spray-coated on a glass sheet and dried at 80C for l minute to obtain a semi-hardened coating. Then, the thus coated glass sheet was immersed in a 20% aqueous solution of phosphoric acid for about 10 minutes. Post treatments were conducted in the same manner as described in Example 18 to obtain a product having a patterned coating.

What we claim is:

l. A decorative article comprising an inorganic coating film having a rugged pattern including cracks, said inorganic coating film comprising a silicate having the formula M OxSiO wherein at is a number of from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R N (R is H, CH OH, -C H OH, CH C H or the like) and (3) groups represented by the formula N=C(NH or a hardening agent in an amount of 4 to 30% by weight based on the silicate, and a pigment.

2. A decorative article comprising an inorganic coating film having a rugged pattern including cracks, and a smooth primer layer, said inorganic coating film comprising a silicate having the formula M OxSiO wherein x is a number of from 0.5 to and M is a member selected from the group consisting of (1) alkali metals belonging to Group [A of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R N (R is H, CH OH, -C H OH, CH,,, C H or the like) and (3) groups represented by the formula N=C(NH or a hardening agent in an amount of 4 to 30% by weight based on the silicate, and a pigment.

3. A decorative article set forth in claim 2 wherein the color of the inorganic coating film is different from the color of the primer layer.

4. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with an amount of from 50 to 500 g/m of an inorganic paint comprising i. a silicate having the formula:

wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of 1) alkali metals belonging to Group 1A of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R,,N (R is H, CH OH, -C H OH, -CH --C H or the like) and (3) groups represented by the formula N=C(NH or ii. a hardening agent in an amount of 4 to 30% by weight based on the silicate,

iii. water, and

iv. a pigment, drying the paint at a temperature between room temperature and C, applying thereon a coating of a solution of an acid in water having an acid concentration of 5 to 40% by weight while the applied coating of paint is in the semi-hardened state, allowing the thus coated substrate to stand for from 0.5 to 30 minutes, moving excess solution by water-washing, and drying the thus treated substrate to harden the coating, said acid having a solubility in water at 20C greater than 5% and being at least one member selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, nitric acid, carbonic acid, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid and glutaric acid.

5. A process according to claim 4 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.

6. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with in a amount of from 50 to 500 g/m of an inorganic paint comprising i. a silicate having the formula.

' wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of l) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R,,N (R is H, CH OH, C H,,OH, CH C l-l or the like) and (3) groups represented by the formula N=C(NH ii. a hardening agent in an amount of 4 to 30% by weight based on the silicate, iii. water, and iv. a pigment, drying at a temperature between room temperature and 150C, applying thereon a coating of a solution of an acid in an alcohol or a mixture of water and an alcohol having an acid concentration of 5 to 40% by weight while the applied coating of paint is in the semihardened state, allowing the thus coated substrate to stand for from 0.5 to 30 minutes, removing the excess solution by water-washing, and drying the thus treated substrate to harden the coating, said acid having a solubility in the alcohol at 20C greater than 5%, being at least one member selected from the group consisting of phosphoric acid, boric acid, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, amlonic acid and glutaric acid, said alcohol having a solubility in water at 20C greater than 20%.

7. A process according to claim 6 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.

8. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with an amount of from 50 to 500 g/m of an inorganic paint comprising i. a silicate having a general formula M OxSiO wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of l alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R N (R is H, CH OH, C H.,OH, CH,,, C H or the like) and (3) groups represented by the formula -N=C(NH ii. a hardening agent in an amount of 4 to 30% by weight based on the silicate,

iii. water, and

iv. a pigment, drying the paint at a temperature between room temperature and 150C, applying thereon a coating of a solution of an acidic salt in water having an acidic salt concentration of to 40% by weight while the applied coating of paint is in the semi-hardened state, allowing the thus coated substrate to stand for from 0.5 to 30 minutes, removing excess solution by water-washing, and drying the thus treated substrate to harden the coating, said acidic salt having a solubility in water at C greater than 5% and being at least one member selected from the group consisting of aluminum chloride, zinc chloride, barium chloride, magnesium chloride, aluminum sulfate, zinc sulfate, magnesium sulfate, aluminum nitrate, zinc nitrate, calcium nitrate, aluminum primary phosphate, zinc primary phosphate and sodium primary phosphate.

9. A process according to claim 8 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.

10. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a subtrate with an amount of from 50 to 500 g/m of an inorganic paint comprising i. a silicate having a general formula M OxSiO wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, triand tetraamines represented by the formula R N (R is H, CH OH, C H OH, CH C H or the like) and (3) groups represented by the formula -N=C(NH ii. a hardening agent in an amount of 4 to 30% by weight based on the silicate,

iii. water, and

iv. a pigment, drying the paint at a temperature between room temperature and C, applying thereon a coating of a solution of an acidic salt in an alcohol or a mixture of water and an alcohol having an acidic salt concentration of 10 to 40% by weight, while the applied coating of paint is in the semi-hardened state, allowing the thus coated substrate to stand for from 0.5 to 30 minutes, removing excess solution by water-washing, and drying the thus treated substrate to harden the coating, said acidic salt having a solubility in an alcohol at 20C greater than 5% and being at least one member selected from the group consisting of aluminum chloride, zinc chloride, magnesium chloride, aluminum sulfate, zinc sulfate, magnesium sulfate, aluminum nitrate, zinc nitrate and calcium nitrate, said alcohol having a solubility in water at 20C greater than 20%.

11. A process according to claim 10 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 900,630 I Dated August 19, 1975 Inventor) Hiroshi Makishima et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In item under "Foreign Application Priority Data" "#7-5'719" should read LI8-5719 Signed and Scaled this twenty-third D a y Of December 1 9 75 [SEAL] RUTH C. MASON Commissioner oj'larenls and Trademarks F ORM PO-105O (10-69) USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTING OFFICE: 

1. A DECORATIVE ARTICLE COMPRISING AN INORGANIC COATING FILM HAVING A RUGGED PATTERN INCLUDING CRACKS, SAID INORGANIC COATING FILM COMPRISING A SILICATE HAVING THE FORMULA
 2. A decorative article comprising an inorganic coating film having a rugged pattern including cracks, and a smooth primer layer, said inorganic coating film comprising a silicate having the formula M2OxSiO2 wherein x is a number of from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, tri- and tetraamines represented by the formula R4-N- (R is H, -CH2OH, -C2H4OH, -CH3, -C2H5 or the like) and (3) groups represented by the formula -N C(NH2)2 or
 3. A decorative article set forth in claim 2 wherein the color of the inorganic coating film is different from the color of the primer layer.
 4. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with an amount of from 50 to 500 g/m2 of an inorganic paint comprising i. a silicate having the formula: M2OxSiO2 wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, tri- and tetraamines represented by the formula R4-N- (R is H, -CH2OH, -C2H4OH, -CH3, -C2H5 or the like) and (3) groups represented by the formula -N C(NH2)2 or
 5. A process according to claim 4 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.
 6. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with in a amount of from 50 to 500 g/m2 of an inorganic paint comprising i. a silicate having the formula. M2OxSiO2 wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, tri- and tetraamines represented by the formula R4-N- (R is H, -CH2OH, -C2H4OH, -CH3, -C2H5 or the like) and (3) groups represented by the formula -N C(NH2)2 or
 7. A process according to claim 6 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.
 8. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a substrate with an amount of from 50 to 500 g/m2 of an inorganic paint comprising i. a silicate having a general formula M2OxSiO2 wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, tri- and tetraamines represented by the formula R4-N- (R is H, -CH2OH, -C2H4OH, -CH3, -C2H5 or the like) and (3) groups represented by the formula -N C(NH2)2 or
 9. A process according to claim 8 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint.
 10. A process for the preparation of a decorative article as set forth in claim 1, which comprises coating a subtrate with an amount of from 50 to 500 g/m2 of an inorganic paint comprising i. a silicate having a general formula M2OxSiO2 wherein x is a number from 0.5 to 10 and M is a member selected from the group consisting of (1) alkali metals belonging to Group IA of the Periodic Table, (2) mono-, di-, tri- and tetraamines represented by the formula R4-N- (R is H, -CH2OH, -C2H4OH, -CH3, -C2H5 or the like) and (3) groups represented by the formula -N C(NH2)2 or
 11. A process according to claim 10 wherein the substrate has a primer coating layer composed of a completely hardened inorganic paint. 